Abstract: A polyalkylene terephthalate polymer, such as polyethylene terephthalate, polybutylene terephthalate, blends or copolymers thereof, and analogous polyester-type engineering thermoplastics, with which has been blended a flame retardant amount of brominated styrenic polymer, such as brominated polystyrene, that, prior to blending, is characterized by (a) containing less than 700 ppm Cl and having a TGA temperature for 1% weight loss of 340° C. or higher; and/or (b) having an actual Mw which is within about 20%, and preferably within about 10%, of its calculated theoretical Mw, the theoretical Mw being based upon the actual bromine content of the brominated styrenic polymer and the Mw of the styrenic polymer reactant used to produce the brominated styrenic polymer; and/or (c) being essentially free of each of the following impurities: (1) ethylene dichloride, (2) bromodichloroethane, (3) dibromochloroethane, (4) dibromodichloroethane, and (5) tribrormochloroethane.

Abstract: This invention relates to a thermally stable brominated polystyrene composition which contains alkali metal base (e.g., NaOH) in an amount less than about 1 wt % such that if the flame retardant is dissolved in bromochloromethane and the resultant solution is extracted with water, the resultant water extract exhibits a pH of at least about 9.0. A preferred composition of this type even when heated to 315.degree. C. for one hour did not undergo darkening--the color remained tan. Comparative samples not containing the base turned black under these same conditions. Especially useful compositions additionally have less than 500 ppm, and better still, less than 100 ppm total Cl, and at least about 67 wt % bromine. Processes for producing the compositions are also described.

Abstract: The impact strength of articles made from a flame-retarded formulated ABS resin containing an impact modifier is increased by forming a concentrate or masterbatch containing the flame retardant and impact modifier, blending the concentrate with ABS resin and extruding the resultant blend.

Abstract: This invention relates to a method for increasing the ultraviolet light stability of articles made from macromolecular materials comprising: forming a flame-retarded formulation containing macromolecular material and a mixture of (i) a first alkylenebis(tetrabromophthalimide) flame retardant having a yellowness index (YI) value ranging from about 20 to about 40 as determined by ASTM D-1925; and (ii) a second alkylenebis-(tetrabromophthalimide) flame retardant having a yellowness index (YI) value (ASTM D-1925) ranging from about 2 to about 15 whereby the uv stability of a test plaque made from the flame-retarded formulation is greater than the arithmetic average of the uv stabilities of a test plaque made from a flame-retarded formulation containing (i) but not (ii) and of a test plaque made from a flame-retarded formulation containing (ii) but not (i).

Abstract: The impact strength of a flame retarded formulated ABS resin containing an impact modifier is increased by masterbatching the flame retardant and impact modifier.